Abstract
The homeotic Antennapedia gene, cloned from the genomic DNA of D. subobscura, was localized on the polytene chromosomes of nine species of the Drosophila obscura group. In all of them, the probe used hybridized on chromosomes equivalent to the E element of Müller's terminology. These results are consistent with the idea that single copy genes do not move around the genome and that chromosomal elements have conserved their genetic identity during evolution.
